MIAMI, FL - DECEMBER 12: LeBron James #6, Dwyane Wade #3 and Chris Bosh #1 of the Miami Heat poses for a portrait during Media Day on December 12, 2011 at American Airlines Arena in Miami, Florida. NOTE TO USER: User expressly acknowledges and agrees that, by downloading and or using this photograph, User is consenting to the terms and conditions of the Getty Images License Agreement. Mandatory Copyright Notice: Copyright 2011 NBAE (Photo by Jennifer Pottheiser/NBAE via Getty Images)

BOSTON (CBSMiami) – The Miami Heat have their proverbial back against the wall as the team makes final preparations for Game 6 of the Eastern Conference Finals against the Boston Celtics.

The Celtics won Game 5 in Miami and head back to Boston fully in control of the series, with a 3-2 lead. Miami looked lost in Game 5 and there was plenty of blame to go around for everyone involved with the team not named LeBron James.

Now, the Heat have to put together a game plan that can slow down Celtics center Kevin Garnett and hope LeBron and Dwyane Wade can score in bunches. It’s the largest challenge the Heat have faced since they lost last year’s NBA Finals to the Dallas Mavericks.

Miami hasn’t responded well to pressure situations since the Big Three of Chris Bosh, James, and Wade came together in the summer of 2010. The same can’t be said of the Celtics. Since 2007, when the combination of Ray Allen, Paul Pierce, Kevin Garnett, and Rajon Rondo came together, the Celtics are 10-1 in potential elimination games.

The presence of Bosh could be the deciding factor in the game. He missed close to a month in the playoffs and while LeBron and Wade could power the Celtics past the Indiana Pacers, the duo needed their third wheel to have a chance against Boston.

But even Bosh’s return in Game 5 didn’t come without some controversy. He was left on the bench at the end of the game, even though he told the press that he was ready to play additional minutes in his first game back from suffering a lower abdominal injury.

Bosh scored nine points and grabbed 7 rebounds (6 offensive) in his 14:23 of action in Game 5. When he was on the floor, Boston changed their defense and it made Miami’s offense that much more dynamic while opening lanes for LeBron and Wade.

Still, he sat during crunch time and his replacements in the starting lineup, Shane Battier and Udonis Haslem scored a total of 8 points, but did grab 16 rebounds.

In Game 6, head coach Erik Spoelstra will have to play Bosh a lot more and likely put him into the starting lineup at center. Bosh can guard Kevin Garnett better than anyone on the Heat’s roster and force Garnett out of the low post on defense.

What Miami needs most is a scoring explosion from the Big Three to force Boston into a shootout and get the transition game keeping the pace fast. Last year, the Big Three could get 70+ points on most nights and if they could do that again, it would greatly help the team.

But what will really make the difference for the heat is if Mike Miller, Shane Battier, Udonis Haslem, Mario Chalmers, and Norris Cole can finally put the ball in the hoop. Combined, the group was 11-35 from the field in Game 5, or just 31.4 percent.

One area Heat fans should watch is behind the three-point line. If Battier, Chalmers, and Miller are the main ones taking three-pointers, the Heat will be much better off. But if James and Wade consistently settle for three-pointers, the Heat will be in deep trouble.

For the Big Three, a loss could very well be the swan song for the trio in Miami. Chris Bosh proved how much he’s worth when he was out for much of the playoffs, which means he would have the most value of any player on the team who could be traded.

Dwyane Wade’s game looks like it’s on the decline after years of leading the Heat and he has turned over the franchise to the phenomenal LeBron James. Wade’s trade value wouldn’t be as high as Bosh’s on the open market.

Still, Heat president Pat Riley may not be ready to throw in the towel just yet. He’ll have to decide on whether to keep Spoelstra if the Heat fails to move on. With some very big coaching names out on the market, it could give Riley a lot of hesitation on his decision.

But talk of that is premature as Miami is still alive in the Eastern Conference Finals against Boston. The team, not just Wade and James, will have to come together in Game 6 to overcome a gritty, polished team with a master motivator at coach in Doc Rivers.

The game tips off Thursday night at 8:30 p.m. from the TD Garden in Boston.